Improvement in rotary measures



D. DAVIS, Jr. & E. WRIGHT.

ROTARY-MEASURE.

Patented Sept. 12, 1876.

N'.1az,1,77.

N. FI'EHS. PHDTO-UTHDGRAFHER. WASHINGTON. D C.

UNITED STATES PATENT OFFICE.

ASSIGNORS TO WILLIAM F. HUDSON, OF SAME PLACE.

IMPROVEMENT IN ROTARY MEASURES.

i Specification forming part of Letters Patent No. 182,177, datedSeptember 12, 1876; application filed April `7, 1875.

'To all ywhom it may concern:

`Be it known we, DANIEL DAVIS, Jr., and

l EDWARD WRIGHT, both of Worcester, in the county of Worcester and Stateof i Massachusetts,`have invented certain new and useful Improvements inSpeed-Indicators; and we do hereby declare .that the following is afull, clear, and exact description thereof, which will enable othersskilled in the art to which it pertains to make and use the same,reference Vbeing had to the accompanying drawing, and to the letters ofreference marked thereon, which form a part of this specification, inwhich- Figurel represents a front elevation of a speedindicator` havingour improvements applied thereto, and Fig. 2 asimilar v iew of amodification Yof the same, a portion of the frame being broken o', toshow the arrangement of the adj usting-screw. Fig. 3 represents a frontview, with the dial-wheel and detachable cappiece removed, and Fig. 4 aVertical transverse section, as taken through the line as a: of Fig. 1LFig. 5 represents a side elevation Fig. 6, a front end view; Fig. 7, arear end view, and Fig. 8 a vertical longitudinal section of theremovable cap-piece; and Figs. 9, 10, and 1l, corresponding views (withthe exception of the sectional view) of a modified form of the removablecap-piece shown in Figs. 5, 6, and 7.

- Fig. 12 represents a side view of a modified or casting the casing orframe and handle in\ one piece, so as to impart the necessary rigidityand strength to the apparatus when applied to the shaft whose speed isto be tested; secondly, in the use of a single-toothed wheel inconnection with a wormfspindle for receiving motion from the shaft to betested, as the means of indicating the speed, instead of two or moredifferential wheels, as heretofore; thirdly, in combining with thistoothed wheel aspring pricker or point in such manner as to prick orimpress the finger or thumb of the hand holding the indicator once forevery revolution ofthe toothed wheel; fourth'ly, in the use inconnection with the worm-spindle of a removable metallic cap-piece',provided onits outer end with slots or sharp angular teeth, for thepurpose of grasping, in apositive manner, the ends of such shafts ashave .pointed terminals, and whose speed is to be tested.

To enable those skilled in the art to make, construct, and use ourinvention, we will now proceed to describe it in detail.

In making the indicator, the casing A, handle B, and lugs C C are castin one piece, as.v 'shown in Fig. 3.

rBhe casing-frame consists of a back plate, a, having a ange or rim, b,cast upon the face of its outer edge, so as to form a` shield orguard-plate for the toothed wheel or gear D. The face of the casing atits center is also provided witha stud, c, upou which is mounted thecombined dial-plate and gear-wheel D.

The ear piecesor lugs@ C are provided with bearings, in which issupported a worm-spin -l dle, E, which, when .fitted therein, is held inplace by an adjusting-screw, e. The spindle E, for this purpose, isprovided with a circumt'eren'tial groove, s, into which the inner end ofthe adjusting-screw e projects. Y

Adjusting-screw .c is set at an angle less than a right angle to theplane oi' the wormspindle, by which arrangement, asits end or the groovewears, it is easily adjusted so as to keep the spindle in its properrelative position with respect to the gear-w'heelotherwise it would failto move the gear-wheel D the proper distance to indicate correctly eachand every revolution of the spindle E.

The gear-wheel may be provided with as many teeth as may be desired, solong as it is graduated or rated accordingly.; but for all practicalpurposesit is deemed better to provide it with a hundred teeth, andgraduate it accordingly. The gear-wheel represented in the drawings isso made, and consequently graduated with division-lines and numbers fromten to one hundred, reckoning by tens; but as many more divisions,lines, and numbers can be marked thereon as may be desired.

An index-finger, I, mayor may not be used j inconnection with thedial-plate. InFigs. 1 and 4 the use of such index is shown. When suchisused, the stud c is made to project slightly beyond the face of thedial-plate D. To the face of this stud the index-finger is then applied,as shown in Fig. 4, and secured by means of the screw d, the stud ebeing provided with a female-screw socket forthe purpose. This screw isturned so as to hold the index firmly in place when adjusted. It alsoserves to confine the`gear D on this stud c, Whether the index I is usedor not.

The Yuse of an index-finger possesses this advantage, that it may beadjusted to the zero or one-hundred point, wherever itniay be, so astostart from that point, when it is desired to test the speed ofa shaft.This is easily effected by simply turning index-finger I to zero-point,for which purpose, .if necessary, screw d may be slightly loosened; or,instead of the adjustable index l, a stationary indexniark may be formedon or cut in the rim b of the casing, at any point whatever.

This mark 'may consist of a simple notch cut in vthe rim, as shown at w,opposite the one-hundred or zero line of Fig. 2; or it may consist of asmall pointer cast on the rim b, and pointing inward toward the dial.

'In the use of this index .point or mark note must be made of the numberof degrees intervening between the zero-point on the dial and theindex-point before applying the instru-l nent to the shaft, that theproper correction may be made in computing the speed; or (and which isbut little trouble todo) the spindle E may be turned by hand until thezero-point and 'the index-pointer coincide, after which the observer hassimply to note the number of complete revolutions ofthe dial-plate,which, together with the odd revolutions indicated by the dial and`pointer, will give the total' number made-during the test.

As this, to a certain extent, may tax the observer considerably, insimultaneously watching the revolutions of the dial and the time, wesimplify the matter by adding to the instrument a spriiig-pricker` m,and which consists of a piece of suitably-bent springwire, the one endof which is secured to the casing A, while the other is left free, andso as to project through the rim b.

'The free end is bent in such manner (as, for instance, as shown in Fig.3) as to form a cam, against the outer side of which a cam-pin,

n, made fast to the inner face of the gear D, is brought to bear onceforevery revolution of the latter. The pin n, acting on the camshapedend of the spring m, forces its end out through rim b in a firm manner,and with sufcient force to apprise any one of the fact whose iingerorthumb is placed over the opening in the rim through which the point ofthe spring m is protruded. This point enables any one, without lookingat the dial, and while his eyes are noting the time on his watch orother time-keeper, to count the number of full revolutions made by thedial-wheel D during any given or required interval of time. As soon asthe action of the cain-pin n passes or is withdrawn from tbe cam-shapedportion of the spring-pricker m, the latter returns to its normalposition-i7. e., within the outer edgeof the opening in rim b.revolutions thus indicated, multiplied by one hundred, added to theoddnninber of revolutionsi-ndicated by the relative position of thezero-,point on the dial-plate with respect to the index-niark on the rimb, will give the total number of revolutions made during the observedtime,always supposing, however, that the stationary index mark orpointer on the riin b and the zero-mark (100) on the dial-platecoincided when the indicator was appliedl to the shaft being tested;otherwise the proper allowance must be made, where the two did notcoincide, by deducting from the total number ythus found the odd numberof revolutions already indicated on the dial-plate before applying it tothe shaft. As a rule, where the spring-pricker or point m projectsthrough the rim, there will be the stationary pointer or notched mark,which, when coinciding with the graduated line marked 100 on thedialplate, will mark zero. Where the stationary mark or pointer on therim b, or the indexfinger I, when used as a stationary index alone,

,does not coincide with a radial line drawn from the center of the dialto the opening in the rim b, through which the pricker m projects, thenthe cam-pin should be so inserted in the dial as to' act on the prickerat the inoinent that the graduated zero (100) line coincides withtheindex-fnger I, or other mark or pointerformed on the rim, which willgive the correct reading by following the rule before described.

Again, by adjustingthecam-pinnimmediatelyin the line of the zero-line,the vindex I may be adjusted to that line wherever it may be withrespect to the opening in the rim b for the passage of the pricker m.

4 This arrangement will enable the indicator to be applied at any timewithout adjusting the gear-wheel, so as to make the zero-line coincidewith the stationary mark at the opening in the rim for the passage ofthe pricker. In this case the difference in degrees between the indexand the pricker-point opening, as indicated upon' the scale, will showthe odd number of revolutions to be deducted from the first revolution`indicated by the pricker-as, for instance, suppose that when 'theinstru- Inent was rst applied, the graduated line marked 60 coincidedAwith the mark at the opening in the rim for the point of the pricker m;index I is then moved'to 100 on the dial. This done, the number ofrevolutions of the dial D, as indicated by the pricker m, is then noted.Then, suppose these were seven, thus indicating seven hundredrevolutions, from The number of wholev casing.

'die E, and into which they take.

hundred and forty revolutions'. To this must then be added the oddnumber of revolutions indicated on the dial, computing for these fromthe pricker-opening in the rim-as, for example, say' that thoserepresented ninety, then the'full number of revolutions would be64M-90:73() revolutions for the observed time. The index I, inl thiscase. acts simply as a reminder of the number of centenary units vwhichthe dial had passed beyond its initial mark, Athese units being easilycomputable from the graduated dial.

In Fig. 3 a modified arrangement of the pricker device is shown, a sideview of the device itselfbeing shown in Fig. 12, it being a simple bentor curved spring-plate riveted at one end to the casing at 4, andcarrying a small pin at its other end, and which is made to projectthrough an opening made in the The end of the cam-pin n as it revolvesacts onV the outwardly-curved face of this spring-plate, depressing it,and thereby forcing itspin out through the opening in the casingagainstthe finger of the operator, as in the former ca se; but thespring-pricker m as arranged is preferred.

The worm 0 on spindle AE is so formed with relation to the teeth of thegear-wheel D that one revolution of the spindle will advance thegear-wheel in its revolution one tooth, and

i that irrespective of the number of teeth on the gear, although, asbefore stated, it is preferred to provide the latter with a hundred, asit facilitates the computation of revolutions made, each revolution ofthe gear indicating one hundred of the spindle.

The end of spindle E is provided with a sharp angular point, p, adaptedto receive motion when forcibly inserted and held in the centering-markformed in the end of a revolving shaft or spindle. As some shafts andspindles, instead of having a central depression or concavity at theirends, are provided with conical or sharp tapering ends, and consequentlycannot impart motion to another spindle provided with a sharp point, we,in order to overcome this difficulty, provide the spindle 'E with adetachable metallic cap-piece or thimble, G, which is so made as to slipover the end of spindle E, the inner end of which is provided withnotches c, corresponding to the angular lines of the pointed endof spin-These notches v are shown at Figs. 7, 8, and ll.

rIhis construction of the cap-piece, when properly adjusted on the endp, insures a positive motion to the spindle E when the cappiece is heldfirmly against the pointed end i of the shaft whose speed is to betested.

To insure a positive motion to the cap-piece G, and through the latterto spindle E, a

couple of notches or slots7 fw, are cut at an angle to each other on theouter end of cappiece Gr, asmall hole or opening being first madethrough its end into the hollow y for the reception of spindle E, theslots w being then cut of a width sufficient to give a sharp edge to thefour teeth thus formed, as seen at Figs. 5 and 6. Thus constructed, whenthese teeth r are pressed with sufficient yforce over the pointed end ofthe revolving shaft-or spindle they will grasp the latterwith suchtenacity as to adhere thereto and turn with it, thereby i causing'spindle E to revolve with it also.

Spindle E is shown as being made cylindrical immediately adjoining itsangular point p; but it may be made angular, in which case the socketpart y of the cap-piece would be made of corresponding shape, in whichevent the notches t at its inner end may be dispensed with.

The teeth r thus formed by notches w, when their upper internal edgebecomes dull from use, may be resharpened by simply grinding square uponthe outer end'of the guard-piece. This form of teeth, however, is betteradapted to spindles having small and very sharp pointed ends than tomore obtuse points.

In Figs. 9,10, and 11 is shown a form of teeth better adapted to thelatter. The cappiece there represented only differs from that shown inFig. 5in the matter of the shape of the teeth, which are more pointed,and recede on 'an outwardly and upwardly inclined line from theperiphery of the central opening back to the external line of the cap,and which give a much stronger hold on theend of the spindle to whichthey are'applied. For self-evident reasons We prefer to use four, or aneven number of teeth, instead of three, or an uneven number.

In` using the indicator it is first examined as to its presentcondition, and, if desired, adjusted to zero-point. This done, a nger orthumb of the operator is pressed over the spot where the pricker m isintended to be protruded. In this position the end of the spindle E,either with or Without the cap-piece G, according to the circumstancesof the case, is pressed against the end of the shaft to be tested, andthere rmly held for the time a1- lotted, the operator counting thenumber of revolutions of the dial if no pricker is used; or, in thelatter case, the number of pricks made on his finger. When done hewithdraws it, notes the numberof odd revolutions indi cated by the dial,and completes the total number according to the methods beforedescribed.

It will be apparent that the same readings can be made by transferringthe graduation lines and numbers, t. e., the scale from the dial-gear Dto the rim b of the casing, for which purpose the rim b may be providedat its upper edge with an inwardly-projecting flange. In this case weprefer to make the Zero point-10() of the scale-immediately above theopening in the rim of the springpricker m, and thence around, as in thecase of the dial. rIhe wheel D should then be provided with an index`mark or pointer, and which we prefer to arrange in a line coincidingwith a radial line drawn through the center of the wheel and the cam-pinln. AThus constructed, the method of using the indicator, from what hasbeen heretofore said, will be obvious, and therefore unnecessary to befurther described.

We are awa-re that speed-indicators have been made in which two or moregears and wheels, having graduation marks and nu-mbers on one, have beenheretofore used in connection with a removable worm-spindle and hingedhandle. 'Such construction we do not claim; but

What we do claim is- ,1. The frame A of a speed-indicator, in which theback plate a and rim b, that protects the gear-wheel D, the stud-pin c,on which the latter is mounted, and lugs C C,

in which the worm-spindle is supported andA turns, and a handle B, areall cast in one piece, substantially as set forth. f

2. A speed-indicator composed of a casing, A, a graduated scale andcorresponding zero index, mark, or point, a worm-spindle, E, having aprojecting end, p, through which it receives motion, either by anangularly-shaped point, p, or a removable metallic cap-piece, G, and asingle gear-wheel, D, the whole being arranged and combined so as tooperate in the manner substantially as set forth.

3'. In combination with the gear-wheel of a speed-indicator carrying acampin, n, a spring point or .pricker, substantially as set forth. f

4. The removable metallic cap-piece'G, constructed with teeth r havingsharp and unyielding edges, substantiallyials and for the purposes setforth.

5. The combination of ,an angularly-arran ged adjusting-screw, e, with aremovable wormscrew, E, provided with fa circumferential groove, s,gear-wheel D, and casing A, of a speed-indicator, substantially as setforth.

6. In a speed-indicator, the combination of an adjustable index-linger,I, with a single gear-wheel, D, having a graduated scale, and a.worm-spindle, E, having a projecting end, p, through which motion isimparted to the latter, the whole operating inthe manner and for thepurposes set forth.

In testimony that we claim the foregoing as our own we aiix oursignatures in presence of two witnesses.

DANIEL DAVIS, JR. EDWARD WRIGHT.

Witnesses:

ABlEL E. WILSON, PHINEHAS BALL.

